The present disclosure relates to a stacked sheet detection device and an image forming apparatus including the same.
In general, an image forming apparatus discharges a sheet with an image formed thereon from a discharge port of a main body portion to a discharge tray. In addition, the image forming apparatus may be provided with a stacked sheet detection device configured to detect that sheets are stacked on the discharge tray exceeding a predetermined allowable level.
The stacked sheet detection device may be called a fullness detection device, for example. The stacked sheet detection device includes a shaft, a first rotor, a second rotor, and a fullness detection sensor. The shaft is rotatably supported above the discharge port. The first and second rotors are provided on the shaft. The fullness detection sensor is configured to detect that the second rotor rotates beyond an allowable range. The first rotor is formed in a region of the shaft corresponding to the width of the discharge port so as to project from the shaft toward the discharge tray. The second rotor is provided in a region of the shaft outside the region corresponding to the width of the discharge port.
When the sheets stacked on the discharge tray exceed a certain level of height, the sheets push up the first rotor, and the fullness detection sensor detects that the second rotor has rotated beyond the allowable range.
In addition, the stacked sheet detection device may include a plurality of first rotors aligned at intervals along the width direction of the sheets. In this case, when the sheets stacked on the discharge tray push up at least one of the first rotors, the fullness detection sensor can detect a rotation of the second rotor. With this configuration, even when the orientation of the sheets stacked on the discharge tray is inclined with respect to the sheet discharge direction, any of the plurality of first rotors is pushed up by the sheets, and the fullness detection sensor can detect the fullness of the sheets on the discharge tray.
In addition, the load of the first rotor is applied to the sheet when the discharged sheet is on the way from the discharge port to the discharge tray. With this configuration, in a case where a sheet is discharged from the discharge port in a curled state, the first rotor restricts an excessive floating of the sheet, thereby preventing a stack failure of the sheets on the discharge tray.